Corner International Stone Sagl. NIW S-Pro Project ject NMi International WIM Standard
Content 1. Background + Approach 2. Scope, Application and Structure 3. Weighing Requirements 4. Procedures for Testing and Certification 5. Benefits of the Standard 2 Presentation NIWS-Project
Background 3 International standards Each with own purpose and (dis-)advantages Parts used in Tenders Nothing for Direct Enforcement for HS-WIM Many National standards All different Often not practical Barrier for market access 3 Presentation NIWS-Project
Approach Goal: International Standard on Weigh-In-Motion Systems Approach: Small Group of Experts on WIM and on Standarisation Covering different; Technologies, Vendors, Countries Published as NMI-Standard Start with Blank sheet of paper Guide with Explanation and Motivation 4 Presentation NIWS-Project
Approach NIWS-Project: Cock Oosterman Nederlands Meetinstituut, (NL) Paul Kok Nederlands Meetinstituut, (NL) Mathias Meijer Nederlands Meetinstituut, (NL) Andy Lees Q-free TDC, (UK) Emil Doupal Transport Research Centre, (CZ) Peter Favai Cestel, (Slo) Randy Hanson Int. Road Dynamics, (Can.) Hans van Loo Corner Stone Int., (CH) 5 Presentation NIWS-Project
Document Scope: Automatic WIM-systems. Performance Requirements Minimum Testing Procedures Application: Technology Independent High Speed and Low Speed Statistical and Legal Applications 6 Presentation NIWS-Project
4 Categories of WIM No Vehicle Dynamics Vehicle Dynamics No Lane changes Lane changes High Speed Low Speed Free Flow Controlled Accuracy of each Legal Applications Legal Applications measurement OOP (CZ) OIML R134 Specified in MPE Legal Approval by NMi High Speed Low Speed Accuracy of average Free Flow Controlled measurement Statistical Statistical Specified in Standard Applications Applications Deviation COS T -323 ??? Buyer-Vendor relation AS TM E1318 7 Presentation NIWS-Project
Document Structure I. General Terminology + Operating Conditions II. Statistical Applications Specifications + Test Protocols III. Legal Applications Specifications + Test Protocols IV. Recommendations (non mandatory) Site selection + Example test protocols 8 Presentation NIWS-Project
Operating Conditions Ranges for: Vehicle Speed, overlapping ranges Temperature* ; -25 C to +55 C Relative Humidity* ; 95% at +55 C Electromagnetic Fields* Mains Voltage Variations* * Based on OIML D11 ; General requirements for measuring instruments No requirements for: Road Conditions or Durability 9 Presentation NIWS-Project
Technical Requirements Vehicle Record Completeness Accuracy requirements for: Completion Rate Length Measurements Classification Rate Resolution requirements for: Date + Time Recording Speed Recording 10 Presentation NIWS-Project
Weighing Requirements Statistical Applications: S (x) [-2 ,+2 ] interval Includes 95% of measurements Class S(5) S(7) S(10) S(15) S(20) GVW 5 7 10 15 20 Axle Group 8 11 15 20 25 Axle Load 10 15 20 25 30 11 Presentation NIWS-Project
Weighing Requirements Legal Applications: L (x) [-MPE,+MPE] interval Includes 100% of measurements Class L(3) L(5) L(7) L(10) GVW 3 5 7 10 Axle Group 5 8 11 15 Axle Load 7 10 15 20 12 Presentation NIWS-Project
Test Procedures Statistical Applications 2 Test Levels; (Initial Verification, In-service Verification) Relation between Buyer and Vendor Legal Applications 3 Test Levels; (Type Approval, Initial Verification, In-service Verification) Independent Legal Approval required Testing and Certification by NMi or National Authority approved by NMi 13 Presentation NIWS-Project
Test Procedures Example: Legal Applications; 3 levels of testing New type of system Type Approval System Type Approval Certificate no. 1 Lab Tests Field Tests System Approval Certificate for no.1 Major maintenance System System Approval Initial Verification no. 2,3,etc . Certificate Field Tests Every x months In-Service System In-Service Verification Certificate no. 1,2,3,etc. Field Tests 14 Presentation NIWS-Project
Test Procedures Field Tests Most common Types of Vehicles Fully Loaded only Test / Type Approval Initial In-Service Application Verification Verifcation n.a. 2 Vehicles, 1 Vehicle, Statistical 10 runs each 10 runs T otal: 20 runs T otal: 10 runs 3 Vehicles, 2 Vehicles, 2 Vehicles, Legal 30 runs each 30 runs each 15 runs each T otal: 90 runs T otal: 60 runs T otal: 30 runs 15 Presentation NIWS-Project
Benefits Combination of: Statistical and Legal Applications High Speed and Low Speed systems Requirements, Test Protocols and Framework for Certification Standard and Informative Guide Independent of: Technology / Type of Sensors Vendor / Manufacturer User / Country 16 Presentation NIWS-Project
Benefits Practical: Short and Simple, Clear Structure, easy to use Based on >100 years of combined experience Balance between: Interests of Vendors and Buyers Weighing-In-Motion and Legal Metrology E.g. Number of test runs should be: Large enough to provide sufficient confidence Small enough to be realistic in daily practice 17 Presentation NIWS-Project
Benefits Open Standard: Use is free of charge Registration at NMi-website Voluntary use of standard As reference In tenders More information: www.nmi.nl www.corner-stone-int.com 18 Presentation NIWS-Project
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